Systems are in use for automatically filling a glass vial with a liquid product and then inserting a resilient, rubber stopper into the open end of the vial. One such system is employed by Abbott Laboratories, Inc., One Abbott Park Road, Abbott Park, Ill. 60064-3500 U.S.A. The system is incorporated in a production line for automatically filling glass vials with a liquid medicament. The production line includes a machine which fills each vial, inserts a stopper in the vial, and secures an overcap on the top of the vial over the stopper. This machine is designated as the "Abboject Vial Filling, Stoppering, And Capping Machine."
The Abboject Vial Filling, Stoppering, And Capping Machine includes a hollow, cylindrical head for receiving the upper, open end of the filled glass vial. Within the head there is an expandable, annular bladder which is inflated to seal around the exterior side surface of the vial just below the top opening of the vial. An arm, holding a stopper at the distal end by means of a conventional vacuum grip, inserts the stopper into the head above the filled vial open end.
A partial vacuum is then drawn within the head below the stopper through passages in the head. This exhausts a substantial portion of the air from the vial above the liquid level and permits the stopper to be forced into the vial so that the bottom of the stopper contacts, or is spaced just slightly above, the liquid in the vial. The stopper can be forced into the vial as the result of the pressure differential existing between the exhausted region below the stopper and the ambient atmosphere. In addition, or alternatively, the stopper can be forced downwardly by the arm.
In any event, proper sealing of the vial with the stopper requires removal of substantially all of the air from above the liquid in the vial. The air is exhausted through peripheral apertures in the cylindrical head which communicate with an annular chamber within the head. A radial bore establishes communication between the annular chamber and the exterior, cylindrical, side surface of the head.
The head is mounted in a vacuum manifold. The vacuum manifold defines a passage communicating with the radial vacuum bore in the head. The vacuum manifold passage has a counterbore for receiving an O-ring which is engaged by the exterior, cylindrical, side surface of the head when the head is properly mounted within the vacuum manifold. The vacuum manifold is connected to a suitable vacuum system for drawing vacuum in the manifold, head, and vial.
Although the above-described system functions generally satisfactorily, it has been found that problems can arise during operation of the production line. In particular, care must be taken to effect a good seal with the O-ring at the vacuum manifold in which the head is mounted.
Typically, different heads are required for different size vials. Accordingly, production workers must change heads when different size vials are to be filled. It has been found that it is difficult to achieve a good seal between the head and the vacuum manifold. When a good seal is not formed, leakage occurs at the O-ring. This results in leakage of ambient atmosphere into the system and a concomitant reduction in the level of vacuum drawing within the vial.
Accordingly, it would be desirable to provide an improved head in which the potential for leakage at the vacuum port is substantially reduced or eliminated.
It would also be beneficial if such an improved head could be embodied in designs that minimize or substantially eliminate structures that easily accumulate liquid or particulate matter and that are difficult to clean. Preferably, such an improved head should have a design that is consistent with aseptic production processes.
Finally, an improved head should accommodate rapid installation and removal by ordinary production workers and should embody a design that minimizes, if not eliminates, the likelihood of incorrect installation.
The present invention provides an improved head which can accommodate designs having the abovediscussed benefits and features.